Socket for small light bulbs



Jan, 6, 1970 P. E. KOERPER AL .5

SOCKET FOR SMALL LIGHT BULBS Filed Jan. 29, 1968 4 Sheets-Sheet 1 f w. 7X 20 @9513 l izo Jan. 6, 1970 P. E. KOERPER ET AL 3,488,526

SOCKET FOR SMALL LIGHT BULBS 4 Sheets-Sheet 2 Filed Jan. 29. 1968 I dmdwfiow P112111 Erharif, Kuerpsr Jan. 6, 1970 P. E. KOERPER ET AL 3,488,6 6

SOCKET FOR SMALL LIGHT BULBS Filed Jan. 29. 1968 4 Sheets-Sheet 5 l v W" mm 24 Jam 1970 P- E. KYOERYPER ET AL 3,488,626

SOCKET FOR SMALL LIGHT BULBS Filed Jan. 29. 1968 4 Sheets-Sheet 4 LSMWJM$MU PhzZZy: Erharai .K'oerpar zZZzam McCoy I United States Patent US. Cl. 339-488 9 Claims ABSTRACT OF THE DISCLOSURE The lamp base is received in a tubular receptacle, open at both ends, supported on bosses that project forwardly from a base member. A contact carrier, which can be integral with the base member, projects forwardly therefrom beneath the receptacle and has cavities opening to 1ts front and sides in which generally flat contact members are received. Edgewise displacement of the contact members is prevented by integral tangs on them, engaging in grooves. The contact members also have integral terminal portions that project sidewardly out of the cavities for wire connections, and forwardly projecting contact fingers engageable with terminal nubs on a bulb base.

with a substantially flat front surface. Mounted on this rear wall, spaced a small distance forwardly of its front surface, was a tubular receptacle that was open at both ends and had its axis substantially parallel to the front surface of the rear housing wall. The base of a lamp bulb was receivable in this receptacle. A contact carrier of resilient insulating material projected forwardly from the rear housing wall across one end of the receptacle and carried a rivet-like metal contact member that had its head portion engageable with a terminal nub on the base of a light bulb in the receptacle.

While satisfactory in most respects, and very successful commercially, the lamp of Patent No. 3,156,416 was not beyond improvement, particularly with respect to its socket.

In practice the contact carrier of that socket was formed integrally with the housing, which was molded of plastic. The resiliency of the plastic, and particularly of the contact carrier, was relied upon to maintain contact pressure between the rivet-like contact member and the terminal nub on the base of a light bulb in the receptacle. However, the contact carrier necessarily had to be rather stiff, with the result that it tended to apply excessive pressure to the bulb and sometimes damaged its terminal.

Despite its stiffness, the contact carrier tended to take a permanent set, so that after a long period of use the contact carrier no longer exerted resilient bias by which contact pressure was maintained between the contact member and the bulb terminal.

Troubles were also caused by the arrangement of the rivet-like contact member, which extended through the contact carrier and had a wire soldered to its end remote from its head. Because of the manner in which the wire had to be secured to the contact member, and the proximity of the contact carrier to the circumferential side wall of the housing, the wire had to have an abrupt rightangle bend adjacent to the contact member, and under the ice influence of time and vibration the wire tended to break at this bend.

With the foregoing considerations in mind, it is a general object of the present invention to provide a socket for a small electric light bulb that has all of the advantages of the socket disclosed in Patent No. 3,156,416 without its deficiencies; and, more particularly, to provide a socket of that character that is very simple and inexpensive but is very durable and dependable.

Another object of this invention is to provide a light bulb socket of the character described] wherein all parts of the socket that are subject to the effects of time or vibration are readily replaceable.

It is also an object of this invention to provide a lamp bulb socket of the character described having certain of its elements formed integrally with a substantially flat base member that can comprise a wall of a lamp housing.

Still another object of this invention is to provide a lamp socket of the character described having a contact member that comprises a very simple and inexpensive metal stamping and having a very simple contact carrier in which the contact member is securely held but from which it can be readily removed for replacement.

With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings. This disclosure is intended merely to exemplify the invention. The invention is not limited to the particular structure disclosed, and changes can be made therein which lie within the scope of the appended claims without departing from the invention.

The drawings illustrate several complete examples of the physical embodiment of the invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

FIGURE 1 is a front perspective view of a lamp housing having therein a socket embodying the principles of this invention, a portion of the housing being broken away to show details of the socket, and with a lamp of the type that the socket is adapted to receive shown in disassembled relation thereto;

FIGURE 2 is a horizontal sectional view of the socket, taken on the plane of the contact members and looking upwardly;

FIGURE 3 is a sectional view taken on the plane of the line 33 in FIGURE 2;

FIGURE 4 is a sectional view taken on the plane of the line 44 in FIGURE 2;

FIGURE 5 is a group perspectiv view of the components comprising the lamp socket of this invention shown in disassembled relation to one another;

FIGURE 6 is a front perspective view of a modified embodiment of the lamp socket of this invention;

FIGURE 7 is a group perspective view of a lamp having a single base terminal and a contact member of a further modified embodiment of the invention, adapted for a lamp of that type;

FIGURE 8 is a front view of a further modified embodiment of the lamp socket of this invention;

FIGURE 9 is a fragmentary vertical sectional view taken on the plane of the line 9-9 in FIGURE 8; and

FIGURE 10 is a perspective view of the insulating guard of the embodiment of the invention illustrated in FIGURES 8 and 9.

Referring now to the accompanying drawings, the numeral 5 designates generally a lamp socket which embodies the principles of this invention and which is adapted to accommodate a small automotive type electric light bulb 6. The socket 5 is mounted on a base member 7 which can comprise the generally flat rear wall of a cup-shaped lamp housing 8, as illustrated in FIGURES l-S, or can comprise a plate-like member, as illustrated in FIGURE 6, that it adapted for mounting in any desired installation. The socket 5, as will be explained hereinafter, can be made either to accommodate a lamp bulb 6 that has a pair of terminal nubs 10 and 10' on its base (see FIGURE 1) or a lamp bulb 6' that has on its base a single coaxial terminal nub 10", as illustrated in FIGURE 7.

The cup-shaped lamp housing 8 is preferably molded of a suitable plastic. It has a circumferential side wall 11 that defines a forwardly opening recess or groove 12 near its front edge in which can be received a suitable lens and gasket (not shown). An integral radially outwardly projecting circumferential flange 13 around the rim of the side wall 11 provides for mounting of the housing.

In general the socket of this invention comprises a tubular receptacle 14 in which the base portion of a lamp bulb is receivable and which is mounted in forwardly spaced relation to the base member 7 with its axis parallel to the front surface thereof, a contact carrier 15 that projects forwardly from the base member, and one or two contact members 16 which are carried by the contact carrier and are adapted to engage the terminal nub or nubs on the base of the lamp bulb.

The tubular receptacle 14 comprises a pair of stamped, horseshoe-shaped members 17 which can be identical with one another, each having a medial bight portion 18 and a pair of oppositely projecting flange or lug portions 19. The bight portions 18 of the two receptacle members are arcuately bent so that they cooperate in defining a tube when their flange portions are flatwise opposed, and the receptacle members ar mounted in that relationship on bosses 20 that are integral with the base member and project forwardly therefrom. Screws 21 extend through aligned holes in the flange portions of the receptacle members and rearwardly into th bosses to hold the receptacle members in place. The bight portion of each receptacle member has an upwardly opening L-shaped groove 22 formed therein for cooperation with the conventional radially projecting stud 23 on each side of the "base of an automotive lamp bulb to provide a bayonet connection by which the bulb is securely but removably held in the base.

The contact carrier 15, which projects forwardly from the base member 7 beneath the bosses 20 and-between them, can be formed integrally with the base member and is of sufficient thickness to have substantial rigidity. Integral ribs 24 can extend from the underside of the contact carrier to the front face of the base member to further insure the rigidity of the contact carrier.

The contact carrier has a pair of substantially deep slit-like cavities 25 therein, both of which open to its front and which respectively open to its opposite sides. Each cavity is inverted T-shaped in transverse section. The cross-member portions 26 of the two cavities, which open both forwardly and sidewardly of the carrier, are separated by a narrow fore-and-aft extending septum 27 in the contact carrier, and are adapted to receive the flat body portions of the contact members 16, as described hereinafter, disposing said body portions in a common plane transverse to the axis of the tubular receptacle 14. The stem portions 28 of the cavities, which open only to the front of the carrier, are spaced to opposite sides of the septum 27 and have upwardly converging opposite side surfaces 29, so that each comprises a fore-and-aft extending groove that has more or less of an inverted V- shaped transverse section along its length.

In the case of a socket intended for a lamp having a pair of terminal nubs 10 and 10' on its base, as illustrated in FIGURES 1-6, two contact members 16 are carried by the contact carrier, one in each of the cavities 25. The two contact members 16 can be mirror images of one another, and each can be stamped from a flat piece of resilient metal. Each is substantially L-shaped, having a flat body portion 30 that is received in the cross-member portion 26 of a cavity 25 in the contact carrier, a forwardly projecting finger 31 that serves as a contact by which a terminal nub on the lamp bulb is engaged, and a laterally projecting terminal portion 32 that extends to one side of the contact carrier to have a wire 33 connected thereto.

The contact finger 31 normally engages a terminal nub on a light bulb under resilient bias by which contact pressure is maintained. It has its front end portion bowed to be upwardly convex, so that it can be readily cammed downwardly by a terminal nub on a light bulb during rotation of the bulb in the receptacle for engagement of the bayonet connection.

A tang 34 that is adapted for engagement in the groove 28 resists displacement of the contact member out of the cavity 25. The tang is struck out of the body portion of the contact member and bent obliquely forwardly and upwardly out of the plane thereof. Note that the tang is rectangular in planform, and particularly that it has square, sharp corners 35 at its front end that bite into the convergent side surfaces 29 of the groove 28 in the contact carrier to resist forward displacement of the contact member. However, the forward and upward inclination of the tang permits edgewise rearward insertion of the contact member into the cavity with such facility that no special tool is required. When the tang is engaged in the groove 28, the side and rear edges of the body portion of the contact member firmly abut their adjacent edges of the cavity to prevent edgewise translatory and rotational motion of the contact member.

It will be observed that although the contact member will not be displaced out of the contact carrier by the vibrational and other forces imposed upon it during normal use, it can be removed for replacement without excessive difficulty by pulling it forwardly with some force.

The terminal portion 32 of the contact member is for the most part flat and coplanar with its body portion. It can have any suitable provision for connection of a wire thereto, and is illustrated as having a tongue 36 struck out of it, either to the top or the bottom side thereof. The tongue is arcuately bent out of its plane to provide a cliplike receptacle in which the bared end portion of a wire 33 can be engaged, as illustrated in FIGURES 2 and 4, to be secured with solder as at 37 in FIGURE 1. It will be observed that a wire can be connected and secured to the contact member before the latter is inserted into the contact carrier, and that the position and arrangement of the terminal portion of the contact member are such as to make unnecessary any sharp bends in the wire that might encourage its breakage.

A conductor 34 can be connected to the receptacle by one of its screws 21 (see FIGURE 2) to serve as a common ground for the circuits in which the two contact fingers 31 are arranged.

FIGURE 7 illustrates a modified form of contact member 16 for a lamp of the type having a single coaxial terminal nub 10" on its base. The contact member 16' comprises a pair of the contact members 16 described above, having their forwardly projecting finger portions widened and integrally joined to provide a single contact finger 31 that bridges the front surface of the septum 27 in the contact carrier.

In the embodiment of the invention illustrated in FIG- URES 8, 9 and 10 the forwardly projecting finger portions 31 of the contact members 16 are protected by a substantially U-shaped insulating guard 41 which also serves to prevent the finger portions from being flexed to such an extent that they might be permanently deformed.

The guard 41, which can be readily molded of plastic, has a bight portion 42 and opposite legs 43 which project upwardly from the bight portion, substantially parallel to the front face of the base member 7, to have their free end portions overlie the flange portions 19 of the horseshoe-shaped socket forming members 17. The legs 43 of the guard are secured to the bosses 20 by means of the same screws 21 that hold the socket forming members in place.

The bight portion 42 of the guard has a substantially L-shaped cross-section, one leg of the L being defined by an upright wall portion 44 that lies in front of the fingers 31, and the other leg of the L being defined by a rearwardly projecting wall portion 45 that underlies the fingers, being spaced slightly below their lower faces.

It will be apparent that the upright wall portion 44 of the guard not only serves to protect the fingers but also serves as a stop that prevents forward displacement of the contact members out of the carrier 15. Hence in a lamp socket of this invention which incorporates the guard 41 the relative shapes of the grooves 28 in the carrier and the tangs 34 on the contact members are not critical, inasmuch as those elements mainly serve as locating means. Where the tangs are not primarily relied upon to prevent forward displacement of the contact members out of the carrier, the rear marginal edge portion of the body of the contact member can be bent slightly out of the plane of the remainder of the body portion, as at 46, so that the contact member engages the top and bottom surfaces of its cavity 25 in the carrier under flexing bias, to be thereby held against flatwise motion as Well as being frictionally restrained against edgewise motion.

The rearwardly projecting wall portion on the guard serves as a stop that defines the downward limit of flexing of the fingers 31 and thereby prevents them from being permanently bent to a position at which they would not make good contacting engagement with terminal nubs on a lamp bulb.

Preferably the bight portion of the guard has a small rearwardly projecting wall element or partition 46 that is disposed between the two fingers 31 to prevent any possibility of contact between them, and it can also have rearwardly extending wall elements 47 that are adjacent to the remote edges of the fingers to cooperate with the partition 46 in guidingly confining the fingers to up and down flexing motion.

From the foregoing description taken with the accompanying drawings it will be apparent that this invention provides a socket for small light bulbs, such as those used in motor vehicle lamps, which is very simple and inexpensive but nonetheless sturdy and dependable; that connections can be made to the socket of this invention without requiring the Wires to have unduly sharp bends; and that all parts of the socket of this invention that are subject to wear are readily replaceable.

What is claimed as our invention is:

1. In a lamp bulb holder comprising a base member having means thereon defining a tubular receptacle open at both ends to receive the base of a lamp bulb:

(A) a contact carrier of insulating material projecting from the base member adjacent to one end of said receptacle and having therein a slit-like cavity that opens to the exterior of the contact carrier;

(B) a contactor member of resilient metal having:

(1) a body portion received in said cavity,

(2) an external finger portion projecting across said one end of the receptacle to be engageable under flexing bias by a terminal nub on the base of a lamp bulb received in the receptacle,

(3) and an external terminal portion to which a conductor is securable;

(C) means on the base for resisting displacement of the contactor member from the carrier, comprising a tang struck out of the body portion of the contactor member, and projecting in a direction opposite to that in which the body portion is insertable into the cavity, said tang being received in a groove in the contact carrier that opens along its length to the cavity and extends in said directions to cooperate with said groove in resisting displacement of the contactor member;

(D) the opposite side surfaces of said groove being divergent toward said cavity;

(E) and said tang having substantially square, sharp corners on its free end that bite into said divergent side surfaces of the groove to resist displacement of the contact member in the direction that the tang projects.

2. In a lamp bulb holder comprising a base member having means thereon defining a tubular receptacle open at both ends to receive the base of a lamp bulb:

(A) a contact carrier of insulating material projecting from the base member adjacent to one end of said receptacle and having therein a slit-like cavity that opens to the exterior of the contact carrier;

(B) a contactor member of resilient metal having:

(1) a body portion received in said cavity,

(2) an external finger portion projecting across said one end of the receptacle to be engageable under flexing bias by a terminal nub on the base of a lamp bulb received in the receptacle,

(3) and an external terminal portion to which a conductor is securable;

(C) said slit-like cavity in the contact carrier also opening to one side thereof;

(D) the contactor member having a substantially flat body portion;

(E) the terminal portion of the contactor member extending edgewise laterally from the body portion thereof to the exterior of the carrier at said one side thereof;

(F) and a tongue struck out of said contactor terminal portion, to which a conductor can be secured.

3. In a lamp bulb holder comprising a base member having means thereon defining a tubular receptacle open at both ends to receive the base of a .lamp bulb:

(A) a contact carrier of insulating material projecting from the base member adjacent to one end of said receptacle and having therein a slit-like cavity that opens to the exterior of the contact carrier;

(B) a contactor member of resilient metal having:

(1) a body portion received in said cavity,

(2) an external finger portion projecting across said one end of the receptacle to be engageable under flexing bias by a terminal nub on the base of a lamp bulb received in the receptacle,

(3) and an external terminal portion to which a conductor is securable;

(C) and a guard member of insulating material secured to said receptacle defining means and having a portion disposed adjacent to the finger portion of the contact member to protect the same and prevent displacement of the contactor member out of the carrier.

4. The lamp bulb holder of claim 3, further charac terized by:

said guard member having a projection which underlies the finger portion of the contactor member at the side thereof remote from the tubular receptacle to prevent excessive flexing of the finger portion by which it might be deformed.

5. In a lamp bulb holder comprising a base member having means thereon defining a tubular receptacle open at both ends to receive the base of a lamp bulb:

(A) a contact carrier of insulating material projecting from the base member adjacent to one end of said receptacle and having therein a slit-like cavity that opens to one exterior portion of the contact carrier;

(B) a contactor member of resilient metal having:

(1) a body portion received in said cavity,

(2) an external finger portion projecting across said one end of the receptacle to be engageable under flexing bias by a terminal nub on the base of a lamp bulb received in the receptacle,

(3) and an external terminal portion to which a conductor is securable;

(C) and a guard member of insulating material fixed with respect to the base member adjacent to said one end of the receptacle and having a portion disposed alongside said exterior portion of the contact carrier to block displacement of the contactor member therefrom.

6. In a lamp bulb holder comprising a base member with a front face, and a tubular receptacle, open at both ends, mounted in front of the base member with its axis substantially parallel to its front face to receive the base of a lamp bulb:

(A) a contact member of fiat resilient metal having:

(1) a substantially fiat body portion,

(2) a finger portion integral with the body portion and projecting edgewise in one direction therefrom. in one direction therefrom,

(3) a terminal portion to which a conductor is securable and which is integral with the body portion and projects edgewise in one direction therefrom,

(4) a tang struck out of the body portion at an inclination to the plane thereof and projecting in a direction toward one edge portion of the contact member;

(B) and a contact carrier of insulating material fixed with respect to the base member and projecting therefrom toward one end of said receptacle, said carrier having:

(1) a slit-like cavity in which the body portion of the contact member is received,

(2) and having means thereon to engage said tang and other portions on the body of the contact member to hold the latter stable in a defined position at which its terminal portion is located externally of the carrier and its finger portion extends across one end of the receptacle for engagement under flexing bias with the terminal nub on the base of a lamp bulb in the receptacle.

7. A lamp bulb holder according to claim 6, further characterized by:

(A) the contact carrier having a pair of said slit-like cavities therein arranged in a common plane and separated from one another by a wall portion on the carrier that extends forwardly with respect to the base member;

(B) there being a pair of said contact members, one for each slit-like cavity and having its body portion received therein and separated from the other by said wall portion on the carrier;

(C) and the finger portions of said contact members extending forwardly across said end of the receptacle for individual engagement under flexing bias with the terminal nubs on the base of a double filament lamp bulb in the receptacle.

8. The lamp bulb holder of claim 7, further characterized by:

a substantially U-shaped guard member of insulating material:

(1) having its legs secured to fixed parts on the base member and (2) having its bight portion substantially L-shaped in cross section with one leg of the L disposed in front of the finger portions of the contact members to protect the same and prevent forward displacement of the contact members out of the contact carrier and the other leg of the L underlying the finger portions at the side thereof remote from the tubular receptacle to prevent excessive flexing of the finger portions.

(3) the bight portion of the guard member also having a fore-and-aft extending wall element that is disposed between the finger portions to prevent contact between them.

9. A lamp bulb holder according to claim 6, further characterized by:

(A) the contact carrier having a pair of said slit-like cavities therein arranged in a common plane opening to the front of the carrier, and separated from one another by a Wall portion on the carrier that extends forwardly from the base member;

(B) and said contact member comprising a stamping having edgewise adjacent body portions received in said cavities and separated by said Wall portion, and extending rearwardly from a single Wider finger portion that projects across said end of the receptacle for engagement with the terminal nub on the base of a lamp bulb in the receptacle.

References Cited UNITED STATES PATENTS 2,985,750 5/1961 Ritz-\Voller et al. 339-188 XR 3,125,299 3/1964 Woofter et al. 339l88 XR KENNETH DOWNEY, Primary Examiner US. Cl. X.R. 240--7.1; 339-125 

